Gomez not match fit, carrying a little knock. So what do you do? Start him, and run the risk of making a minor injury more of a thing? Or keep him on the bench, hope you won't need to call on him, but if you do, then it is only for a portion of the game, depending on when he comes in.
We all know the decision Klopp and the team took, and with all the data they have, plus their own eyes as they look at them in training, plus the conversations they have with the players themselves, they made the call.
We can Monday morning quarterback it all we like, but they made a reasonable enough decision.
As for Zaha, he has given plenty of defenders in the league a lot of trouble over the years, especially on the break. It's unfortunate that it happened with Nat Phillipps on the pitch, but he has done it to plenty of defenders who we would consider to be better than Phillipps.
Nat Phillipps is a solid citizen. Definitely good enough for lower Prem. If he plays in a team where the line isn't so high, he will be a stout defender for someone - decent enough on the ball, brave, strong in the tackle, and excellent in the air at the back.
It is odd to me that someone hasn't bought him yet. It might be because of our valuation, or it might be because clubs don't rate him as much as I do. Or it might be that they sense Liverpool's valuation will drop, and they will get themselves a bargain late in the window.